Allah is the Creator, and the result of this is the earth, the mountains and everything we see. Does that mean that Allah is part of His creation because it is the result of His attribute of being a creator?

We have to differentiate between “creation” as an attribute of Allah, and the created beings that Allah has created. Allah’s attribute of “creation” basically means that Allah creates. So, we say that Allah’s act of creating is His attribute that is not created. As for the created being, then this is obviously created.

The same can be said with all of Allah’s other attributes.

And Allah knows best.